Houston, J.R., 2015. Shoreline response to sea-level rise on the southwest coast of Florida.

The state of Florida has a unique database of shoreline position measured about every 300 m and dating back to the mid-1800s that presents an opportunity to determine the effects of sea-level rise on shoreline position. In addition to sea-level rise (Bruun rule initially assumed), data are available on the southwest coast of Florida for other factors contributing to shoreline change, including beach nourishment, inlet shoal change, and longshore sediment transport. The sum of these factors should have caused significant shoreline recession, but instead the average shoreline position of this coast was stable during the early period from the 1800s to the 1970s (prior to beach nourishment) and strongly accretive from the 1800s to the 2000s. When the Bruun rule is used, shoreline change predicted by the sum of the factors compares poorly with measured data, but it compares quite well when the Dean equilibrium concept is used. The Dean equilibrium concept says that under wave action and with sufficient available offshore sand, shorelines will advance with sea-level rise due to onshore sand transport. Long-term shoreline change data for most of the Florida east coast and the Dutch central coast also support the Dean equilibrium concept. The source of the onshore sand transport in southwest Florida is identified. Sea-level rise results in long-term shoreline advance rather than recession for shorelines with sufficient onshore sand movement from beyond closure depth to the active profile, probably during episodic storms.

Harman, B.P.; Heyenga, S.; Taylor, B.M., and Fletcher, C.S. 2015. Global lessons for adapting coastal communities to protect against storm surge inundation.

Coastal inundation as a result of global sea-level rise and storm surge events is expected to affect many coastal regions and settlements. Adaptation is widely accepted as necessary for managing inundation risk. However, managing inundation risk is inherently contentious because of many uncertainties and because a large number of stakeholder interests and values are mobilised. For these reasons, among others, adaptation progress in many countries has been slow. Despite progress in adaptation research, a critical knowledge gap remains regarding the appropriateness and applicability of various adaptation options, including their transferability between different coastal settings. We review the international literature on coastal adaptation options (including options to defend, accommodate, or retreat) to manage inundation risk, focusing on developed, liberal economies of Western Europe, North America, the U.K., Australia, and New Zealand. In doing so, we identify the favoured strategies adopted by these nations, probe the influence of physical and institutional context on the selection of these options, and identify what lessons might be exchanged or future directions inferred. The review places particular emphasis on the Australian experience as a comparative device to highlight some important distinctions. These distinctions focus on how government responsibility is exercised, including the degree of centralisation; the “fit” of options to local coastal environments and social values (i.e. their suitability and acceptability); and the transferability of different adaptation options in international contexts.

Adomat, F. and Gischler, E., 2015. Sedimentary patterns and evolution of coastal environments during the Holocene in central Belize, Central America.

Coastal lagoons, marshes, and swamps cover large areas of the Belize coast. Twenty-six sediment cores collected along five transects along the central Belize coast and 58 radiocarbon dates from these cores reveal stratigraphic details of coastal sediment deposition. Marine inundation of the mainland and coastal lagoon formation started between 7980 calendar years before present (cal BP) and >5547 cal BP. As a response to sea-level rise during the Holocene transgression, facies retrograded toward the coast, as seen in marginal marine overlying brackish mollusk faunas. Evidence for late Holocene progradation of facies due to sea-level stagnation is largely lacking. The occurrence of landward thinning sand beds, hiatuses, and marine fauna in lagoonal successions are indications of event (overwash) sedimentation. Sediments recovered are largely of Holocene age (<7980 cal BP), overlying Pleistocene sections. Analyses of sediment composition and texture, radiocarbon dating, and mollusk shell identification were used to describe and correlate sedimentary facies. X-ray diffraction analyses have identified quartz as the dominant mineral, with the Maya Mountains as main source of coastal lagoon sediments. The most common sedimentary facies include peat and peaty sediment, mud, sand, and poorly sorted sediments. Pleistocene soil forms the basement of Holocene sediments. Holocene mud represents lagoon background permanent sedimentation. Peats and peat-rich sequences were deposited in mangrove swamp environments, whereas sandy facies mainly occur in the shoreface, beach, barriers, bars, barrier spits, and overwash deposits. Facies successions could be identified for each locality, but it has proven difficult to correlate the stratigraphic sequences, especially among localities. These differences among the five locations studied suggest that apart from regional influence such as sea-level rise, local environmental factors such as small-scale variation in geomorphology and resulting facies heterogeneity, connectivity of the lagoon with the sea, antecedent topography, and river discharge were responsible for coastal sedimentation and lagoon development in the Holocene of Belize.

Moran, K.L.; Mallinson, D.J.; Culver, S.J.; Leorri, E., and Mulligan, R.P., 2015. Late Holocene evolution of Currituck Sound, North Carolina, USA: Environmental change driven by sea-level rise, storms, and barrier island morphology.

The Holocene evolution of Currituck Sound, North Carolina, is investigated using geological data and a hydrodynamic model to understand how this depositional basin changed in response to sea-level rise and regional climate patterns. Five depositional units (one Pleistocene and four Holocene) are defined based on geophysical surveys, lithofacies, biofacies, and geochronological data. The earliest Holocene unit (ca. 5000 cal YBP) represents a midsalinity (10–25‰) sand shoal above the transgressive ravinement surface. This unit is overlain, successively, by (1) a freshwater swamp forest deposit, (2) a relatively saline (25–35‰) back-barrier estuarine deposit associated with increased inlet activity, and (3) a mid- to low-salinity (<10‰) deposit that is typical of modern (post-1827) Currituck Sound, a back-barrier estuary with no inlets in the barrier island. Geomorphic reconstructions provided the boundary conditions input to hydrodynamically model tide and current patterns and to constrain the probable size and location of inlets. The evolution of this system depends on sea-level rise and barrier morphology, regional hydrological factors, and regional climatic conditions, which modulate storm impacts and inlet activity along the fronting barrier system. The late Holocene stratigraphy reflects climate variability also recorded in the sediments of Chesapeake Bay (to the north) and Pamlico Sound (to the south) and is consistent with an increase in tropical cyclone activity during the Medieval Climate Anomaly and subsequent decrease in tropical storm activity since ca. 500 cal YBP.

Mattheus, C.R. and Fowler, J.K., 2015. Paleotempestite distribution across an isolated carbonate platform, San Salvador Island, Bahamas.

Sediment cores were collected from coastal ponds across San Salvador Island, an isolated Bahamian carbonate platform, and integrated with aerial photographs and field-survey data to provide insight into how spatially variable storm records are at the island scale and what drives this variance. A better understanding of local tempestite generation and preservation potential is crucial for correlating events across more regional scales. Sandy storm layers, products of beach overwash and/or high-energy aeolian transport from the shore into coastal ponds, are easily distinguished from flocculated carbonate muds, microbial mats, and other organics that ordinarily sequester in the stagnant, low-energy coastal water bodies. Interpreted paleotempestites do not correlate well between studied ponds using a strictly stratigraphic approach, although all sites investigated are situated within 150 m of a sandy beach, are similar in size and morphology, and coastal terrains across the small island are comparable. While wrack lines show that individual storms produce surges that vary in height along the island's 60 km-long coastline, differences in the spatial distribution of storm deposits cannot be explained solely as a function of variable surge heights, storm trajectories, and shore aspect; they also reflect intrinsic, biogeomorphic variables such as pond-fringing vegetation characteristics and coastal geomorphic configuration. A complete storm chronology for the island is not generated in any single pond location, and diagenetic processes compound this variance, producing a high degree of spatial heterogeneity of storm records. Nonetheless, the Caribbean-wide Hurricane Hyperactivity Period is distinguished in core from the modern period of relative inactivity by an up-core transition from sandy, stratified pond deposits containing storm layers to heavily bioturbated sediments indicative of low-E deposition. This facies transition, recognized across the island, provides a regional correlation tool for evaluating the distribution of paleotempestites within context of major climate regimes.

Lychagin, M.Yu.; Tkachenko, A.N.; Kasimov, N.S., and Kroonenberg, S.B., 2015. Heavy metals in the water, plants, and bottom sediments of the Volga River mouth area.

Deltaic landscapes occupy a special place in environmental geochemical studies of water bodies. Their ecotone position at the land–sea boundary determines the biological richness of the deltaic ecosystems and creates a unique variety of landscape–geochemical conditions. The Volga River delta is one of the largest in the world. It serves as a geochemical “focus” that reflects the character of fluxes of substances of natural and anthropogenic origin in the entire system of the Volga basin. This paper presents the results of long-term environmental geochemical research of aquatic landscapes in the mouth area of the Volga River. The study has shown the high spatial and temporal variability of the chemical element migration in the area due to the influence of hydrodynamic conditions, variations in water and sediment discharge, and local features of the aquatic systems that determine their geochemical identity. The environmental geochemical conditions of the Volga delta are still relatively safe, especially compared with many other estuaries of the major rivers. Contamination of aquatic systems is manifested mainly in excess of heavy metals (Cu, Pb, and Cd) in suspended matter over the global background values, most notably in the flood period. The content of heavy metals in the water and sediments during the most recent decades remains low; pollution of the bottom sediments is largely insignificant and local.

Vinita, J.; Shivaprasad, A.; Revichandran, C.; Manoj, N.T.; Muraleedharan, K.R., and Binzy, J., 2015. Salinity response to seasonal runoff in a complex estuarine system (Cochin estuary, west coast of India).

The hydrographic conditions in Cochin estuary are investigated using longitudinal measurements of salinity profiles during a 1-year period. The estuary transformed from salt wedge conditions during the wet season to a partially or well-mixed state during the dry season. During high runoff months (June–September) and moderate runoff months (October–December and May), the salinity structure is a strong function of variations in river runoff, and the estuary responds coherently to episodic inputs of freshwater. However, during the period from January to April, the dependence of the salinity field on runoff was weakened by axial diffusivity. The salt transport was a balance between seaward flux induced by river runoff and tidally induced diffusive landward flux. The latter dominated in almost all sections along the estuary except at the upstream end, increasing the salt content of the estuary. The computed horizontal diffusion coefficients ranged from 5 to 704 m² s⁻¹. The flushing time of Cochin estuary ranged from 1 to 2.5 days during the wet season. During the dry season, the tide-driven flushing time was 8.7 days. The results represent an important benchmark against which numerical models should be measured and will be useful for developing a better understanding of biological and chemical distributions within the estuary.

Han, Y.; Zhan, J-M.; Su, W.; Li, Y.S., and Zhou, Q. 2015. Numerical simulation of in-line response of a vertical cylinder in regular waves.

In-line response of a flexibly mounted, vertical cylinder in a series of regular waves was studied with numerical simulation. A dynamic mesh scheme and a laminar flow model were adopted. The experimental and simulated time histories of five wave gages and the response of the cylinder were compared. At low-incident wave frequencies, although the ratios of the diameters of the cylinders to the wavelength were small, the oscillating cylinder had little influence on the flow field. The numerical responses of the cylinder were in very good agreement with the experimental data. As the frequency of the incoming wave increased, the diffraction effect caused by the cylinder became significant, and the simulated responses of the cylinder were slightly weaker than those of experiment. When the incident wave frequency approached the natural frequency of the cylinder, the cylinder oscillated in resonance, and the flow field was strongly influenced. The wave height behind the cylinder was reduced. At high-incident wave frequencies, the Reynolds number increased, and the numerical response of the cylinder became stronger than those of experiment. In conclusion, the numerical results of the cylinder response agreed well with the results of the experimental model. To improve the predictive accuracy of the numerical model, further study, such as with the use of a turbulence model, should be carried out in the future.

Elbisy, M.S., 2015. Sea wave parameters prediction by support vector machine using a genetic algorithm.

The prediction of sea wave parameters is important for the planning, design, and operation of coastal and ocean structures. Many empirical methods, numerical models, and soft computing techniques for wave parameter forecasting have been investigated, but such forecasting is still a complex ocean engineering problem. In this study, the support vector machine (SVM) approach, using various kernel functions, is presented for wave parameters prediction in an attempt to suggest a new model with superior explanatory power and stability. A genetic algorithm is used to determine the free parameters of the SVM. The SVM results are compared with the field data and with backpropagation and cascade-correlation neural network models. Among the models, the SVM with a radial basis function kernel provides the best generalization capability and the lowest prediction error and can therefore be most successfully used for the prediction of wave parameters.

Kidder, G.W.; White, S.; Miller, M.F.; Norden, W.S.; Taylor, T., and Disney, J.E., 2015. Biodegradable grids: An effective method for eelgrass (Zostera marina) restoration in Maine.

Restoration of eelgrass (Zostera marina L.) beds is often done by tying vegetative plants to wire grids and transferring them to the ocean bottom. In our experience, rhizomes can grow over the grids, resulting in a significant loss of transplants when the grids are removed. We have tested two other methods that circumvent this problem that have proved successful in Maine. First, we “stapled” eelgrass plants into subtidal areas using bent bamboo skewers. This method is effective and avoids grid-removal losses but is slow, is laborious, and requires workers with equipment. More recently, we constructed a novel biodegradable grid (BDG) with spruce side rails, laced with sisal twine and weighted with small sandbags. We find that BDGs are even more successful than wire grids at establishing transplants and that the losses from grid removal are eliminated. BDGs are an effective way of involving citizens in eelgrass restoration projects while increasing the success rate of transplants and saving labor.

Wen, F. and Wang, J.H., 2015. Response of layered seabed under wave and current loading.

Wave and other environmental loadings in the ocean are the main factors affecting seabed stability and the safety of marine structures. Most previous literature has considered seabed response in a layered seabed under wave loading or in a single soil layer only under combined wave and current loading. In this article, a two-layered seabed, subjected to combined wave and current loading, is considered. The influence of currents on the stratified seabed response is investigated initially. The results indicate that a following current will aggravate the instability of the seabed, either in the form of liquefaction or shear failure. The effects of stratification on the seabed response were also studied. Numerical results reveal that upper layer of the seabed will become more stable as the permeability ratio (k₁ : k₂) increases, where k₁ and k₂ are the permeability of upper and lower layer of the seabed, respectively. The thickness of each layer of the seabed also affects its stability. For example, the upper layer is apt to be more unstable when the thickness of the lower layer of the seabed (h₂) is equal to about one-fifth of the wave length (L/5). Analysis of the seabed reformation in relation to engineering practice shows that replacing or adding a layer onto the original seabed can both prevent liquefaction effectively, and the approach of adding a layer has the better potential to prevent liquefaction, but those treatments have a lesser effect on the maximum depth of shear failure in the original seabed.

Cho, C.-W.; Song, Y.-S.; Kim, C.-K.; Kim, T.-I.; Han, J.-S.; Woo, S.-B.; An, S., and Choi, T., 2015. A modeling study on hypoxia formation in the bottom water of the Youngsan River estuary, Korea.

Hypoxia negatively affects marine environment and organisms and is an important indicator of estuarine water quality. We conducted a field survey and a three-dimensional particle transport modeling study to investigate summer hypoxia formation in the bottom water of the Youngsan River estuary (YRE). The field survey showed that dissolved oxygen (DO) decreased upstream and toward the bottom. The lowest DO, at 4.4 mg L⁻¹, occurred in the bottom water in front of the estuary dam. We found persistent two-layer estuarine circulation driven by freshwater discharge, which is the main mechanism for delivering offshore water mass upstream. Applying the total oxygen consumption rate (0.50 mg L⁻¹ d⁻¹) observed in the estuary, the offshore water mass entering the estuary loses as much as 4.4 mg L⁻¹ of oxygen during the average travel time (8.8 days) from the mouth of the estuary to the dam. These findings indicate that bottom hypoxia can be formed in front of the estuary dam in summer if offshore water mass with relatively low DO (<8.4 mg L⁻¹) enters the estuary. For the sound management of water quality in the YRE, therefore, we recommend improving the quality of the offshore water entering the YRE and also decreasing oxygen demand by reducing nutrient loading from the YRE dam.

Aquino da Silva, A.G.; Stattegger, K.; Schwarzer, K.; Vital, H., and Heise, B., 2015. The influence of climatic variations on river delta hydrodynamics and morphodynamics in the Parnaíba Delta, Brazil.

In this work, we present a baseline study on the geo-environmental, morphodynamical, and hydrodynamical conditions of the Parnaíba River and its mouth, the Parnaíba River Delta (PRD). The outline of the PRD indicates that waves are the major forcing factor for delta development. Furthermore, the shape of the delta suggests that there is a considerable degree of asymmetry in its formation. The asymmetry is the result of coastal current influence on the reworking of the sediments that are discharged by the river. To investigate the hydrodynamic conditions of the area, field measurements were conducted on the river, offshore of the PRD, and on the tidal channels of the west part of the delta. At these locations, the currents, salinity, temperature, and tidal dynamics were measured. In addition, a time series of rainfall, river discharge, and suspended sediment concentration (SSC) were obtained from Brazilian governmental agencies. The interpretation of all of the data was used to determine how they interact to characterize the hydro- and morphodynamics of the PRD. Harmonic analysis was of high importance in the analysis of the time series, and it was employed to identify longer periods presenting similarities in terms of meteorological conditions. This allowed determination of the interconnection between rainfall, river discharge, and SSC with the occurrence and intensity of the El Niño-Southern Oscillation. The influence of river discharge, rainfall, and SSC on shoreline change was demonstrated through the analysis of decadal shoreline evolution using a series of LANDSAT images covering the period from 1981 to 2009. The analysis revealed that most changes occurred westward from the PR mouth. Changes in spit migration velocity were correlated to variations in riverine sediment yielded as a result of variations of river discharge and SSC.

Bickford, W.A.; Needelman, B.A.; Miller, M.W., and Hutchins, E.G., 2015. Prescribed fire increases soil temperatures through canopy removal in a Mid-Atlantic brackish marsh.

Canopy removal produced by prescribed fire may influence soil temperatures, which has the potential to affect conditions for plant growth and other temperature-related soil functions. We assessed the changes in soil temperatures following prescribed fire using manipulative treatments in a brackish tidal marsh in the Blackwater National Wildlife Refuge in Dorchester County, Maryland, using two randomized complete block experiments. At No-Burn sites, treatments were canopy removal through clipping and ash/biochar deposition. At Annual Burn sites, the treatment was canopy replacement using a constructed frame and senesced vegetation. Soil temperatures were continuously measured over a period of 6 months (one growing season). Ash/biochar deposition did not affect soil temperatures. Mean daily soil temperatures at a depth of 5 cm were as much as 2°C higher in plots with canopy removal at the No-Burn sites and as much as 2.9°C lower in plots with replaced canopies at the Annual Burn sites. Canopy removal was also associated with increased soil temperatures at the 20-cm depth. Soil temperature effects were lower during a period of high water levels early in the season than they were during a mid-season period with lower water levels. Prescribed fire causes increases in soil temperatures through canopy removal and therefore may positively influence plant productivity in species that can take advantage of an earlier growing season and/or higher growing season temperatures.

Chao, M.; Shi, Y.; Quan, W., and Shen, X., 2015. Distribution of macrocrustaceans in relation to abiotic and biotic variables across the Yangtze River Estuary, China

In this article, we report on a study of the spatial and seasonal distribution of macrocrustaceans and reveal the correlation between macrocrustacean community and environmental variables in the Yangtze River Estuary, China. A total of 44 species belonging to 21 families were identified during sample collection in May, August, and November 2010 and February 2011. Species richness of four survey trips showed significant differences among seasons and zones. The most frequent species identified were Neoeriocheir leptognathus (M.J. Rathbun, 1913) in February and May; Palaemon gravieri (Yu, 1930) in August; and Exopalaemon annandalei (Kemp, 1917) in November. The mean macrocrustacean abundance in May 2010, August 2010, November 2010, and February 2011 was 24.94, 19.82, 29.46, and 17.14 individuals/1000 m², respectively. The distribution of macrocrustaceans demonstrated a significant variation among seasons and zones based on PERMANOVA analysis. In terms of the value of species dominance, P. gravieri was the most dominant species throughout the study period, which composed 27.4% of the total specimens obtained. The distribution of macrocrustacean abundance in relation to biotic and abiotic variables was studied by multivariate analysis of macrocrustaceans using cluster and canonical correspondence analyses. These results demonstrated three typical classifications of communities and a significant relationship between macrocrustaceans and environmental variables. Salinity was the determining factor for spatial distribution of species and temperature for species occurrence on the entire estuarine scale. Additionally, biotic variables such as abundance of Polychaeta, abundance of primary production, and abundance of estuarine resident fishes also found significant variables that correlated with the abundance of macrocrustaceans in the Yangtze River Estuary. The study on relationship between macrocrustaceans and environmental variables provided baseline information for future ecological risk assessment in the Yangtze River estuary.

Moore, G.E.; Grizzle, R.E.; Ward, K.M., and Alshihi, R.M., 2015. Distribution, pore-water chemistry, and stand characteristics of the mangroves of the United Arab Emirates.

Mangroves are the dominant coastal vegetation of the United Arab Emirates (UAE), occupying one of the driest mangrove habitats in the world. However, published estimates of mangroves do not represent current conditions for the country as a whole. This study provides an up-to-date estimate of UAE's mangroves, summarizing their habitat characteristics, stand heights, and pore-water conditions. Estimates of mangrove cover are based upon remote sensing, aerial photointerpretation, and field verification. Our results document more mangroves than previously estimated for Abu Dhabi and the nation altogether. Mapped areas were classified into three descriptive density cover classes to facilitate interpretation of the data: low (<10%), moderate (10–75%), and high (>75%). The high-density class reflects prior national estimates for mangrove coverage (roughly 3613 ha), while moderate- and low-density classes contributed an additional 5659 ha and 4344 ha (respectively) to the national total. The largest contiguous mangrove area was 710 ha, while the smallest mapped area was 0.03 ha. Mapped mangrove habitat types included fringe, basin, and overwash, with average heights of 3.36 ± 0.25 m and density of 61.83% ± 5.01%. Stand height and pore-water sulfide concentrations were significantly different between habitat types, while stand density, pore-water salinity, and redox potential were highly variable. In sum, approximately 13,616 ha of mangrove area was mapped, roughly three times more than prior estimates. This is the first study in recent years to document the full areal extent of mangroves and associated stand characteristics across the seven emirates.

Brutsché, K.E.; Wang, P.; Rosati, J.D., and Beck, T.M., 2015. Evolution of a swash zone berm nourishment and influence of berm elevation on the performance of beach-nearshore nourishments along Perdido Key, Florida, USA.

A nourishment was placed within the swash zone along eastern Perdido Key, Florida, in 2011–2012 using maintenance-dredged material from nearby Pensacola Pass, referred to here as a “swash zone berm nourishment.” The study area was divided into three sections, the swash zone berm project and two adjacent areas to the west and east, and was monitored with time series beach surveys. The performance of the 2011–2012 nourishment with a constructed berm elevation of 0.91m North American Vertical Datum 1988 (NAVD88) was compared with two previous nourishments in 1985 and 1989–1991, with 3.0 m NAVD88 and 1.2 m NAVD88 elevations, respectively. The low elevation for the 2011–2012 nourishment allowed natural overwash processes to occur frequently, which resulted in net onshore sediment transport and growth of the active berm. The swash zone berm evolved back to the natural equilibrium profile shape maintained in the study area within 8 months. The high–wave energy conditions associated with the passages of Tropical Storm Debby and Hurricane Isaac accelerated the equilibrium process. Sediment volume gain west of the project area due to longshore spreading of the nourishment occurred mostly in the trough between the shoreline and the bar, rather than on the dry beach. In terms of rate of shoreline retreat, the short 1.2-km 1985 nourishment performed the poorest with a rate of 40 m/y. The long 7.3-km 1989–1991 nourishment performed the best with a retreat rate of 11 m/y. This suggests that high berm elevations do not necessarily lead to better nourishment performance. Instead, longshore extent of a nourishment may dominate project performance. Furthermore, the very high nourishment density of 1550 m³/m did not improve nourishment longevity.

Styles, R., 2015. Flow and turbulence over an oyster reef.

Simultaneous measurements of near-bed flow and turbulence were collected on opposite banks of an intertidal channel in the North Inlet/Winyah Bay National Estuary Research Reserve. One bank supported an extensive cover of oysters and the other a mixture of sand and mud. The measurements allow comparisons of flow and turbulence characteristics in a similar flow regime but widely varying roughness conditions. Near-bed velocities are higher over the sandbank and occur during the maximum flood portion of the tidal cycle. In contrast, turbulence parameters are higher over the oyster reef, resulting from the presence of the larger roughness elements. Turbulent kinetic energy and Reynolds stress components increase as a function of flow speed, consistent with equilibrium boundary layer shear flows. For some bursts, the energy spectrum exhibits a −5/3 slope, indicating a defined inertial subrange. Dissipation over the oyster bank is on the order of 10 cm² s⁻³ during maximum flood, when the near-bed current speeds are greatest. Drag coefficient and hydraulic roughness are likewise greater over the oyster bank, with average values of C_D = 0.025 and z₀ = 0.78 cm compared with C_D = 0.004 and z₀ = 0.02 cm for the sandbank. The analysis reveals a simple roughness formula for oysters in which the physical bottom roughness is equal to 5 times the average height of the oysters.

Pivovaroff, A.L.; Swift, C.; Battaglia, L.L.; Kunz, B.; Platt, W.J., and Yoder, C.L., 2015. Physiological profiles as indicators of response to hurricane disturbance for three coastal wetland species.

Hurricanes alter light and water availability via canopy damage and storm surge delivery and are expected to intensify with climate change. Plant species respond to environmental changes by making physiological adjustments in situ or through distribution changes. Three years after Hurricane Katrina, we compared functional traits and water relations among three species along the coenocline at Weeks Bay National Estuarine Research Reserve, Fairhope, Alabama, U.S.A. Based on posthurricane distribution changes for these species, we hypothesized that (1) Cladium mariscus, whose distribution expanded slightly, is responsive to increased light availability in the disturbed forest at the landward end but is strongly limited by water stress at its seaward edge; (2) Baccharis halimifolia, whose distribution shifted and abundance increased posthurricane, is responsive to increased light availability, cannot tolerate very low light levels or water logged soils, but can tolerate moderate salinity; and (3) Morella cerifera, whose distribution remained unchanged, would show little or no difference in measured functional traits and water relations at its landward vs. seaward edges. Cladium mariscus showed decreased water potential (Ψ) at its seaward edge, but leaf mass per area (LMA) did not vary as forest cover increased landward. Baccharis halimifolia exhibited lowest LMA and highest Ψ in the middle of its distribution, but was least vulnerable to cavitation (Ψ₅₀) with increased forest cover. Morella cerifera exhibited no difference in water stress, wood density, or Ψ₅₀ across its distribution. Our results suggest differences in physiological response to light availability and water stress may affect the postdisturbance distribution of plant species and influence changes in distribution of species exposed to chronic sea level rise.

Tong, C.; Huang, J., and Jia, Y., 2015. Small-scale spatial variability of soil methane production potential and porewater characteristics in an estuarine Phragmites australis marsh.

High temporal and spatial variability is a problem when quantifying methane flux from wetland soils. Spatial variability of methane production at the landscape scale has been investigated for different wetlands, but few studies have examined soil methane production at the small scale. Here, we investigated small-scale spatial patterns of soil methane production potentials and concentrations of porewater acetate, dissolved CO₂, , , and soil dissolved organic carbon (DOC) in a brackish Phragmites australis marsh of the Min River estuary, southeast China. Sampling was performed for an area of 1.6 × 1.6 m to a depth of 30 cm (5-cm intervals) using a grid of 0.4 m resolution. Data were interpolated by an inverse distance moving average weighted method. Large differences in soil methane production potentials were detected between each grid across lateral space. Coefficients of variation (CVs) often exceeded 100%, indicating very high spatial variability in methane production potentials on the small scale in the horizontal direction in brackish P. australis marsh. Results also showed no significant spatial autocorrelation in methane production potentials at the small scale. Topsoil (0–5 cm) showed the greatest methane production potentials (1.07 μg g⁻¹ d⁻¹). The CVs of acetate and dissolved CO₂ concentrations were always <50%, except in the topsoil, which indicates a lower spatial variability of the concentrations of substrates compared with methane production potentials. Spatial autocorrelation in porewater acetate and dissolved CO₂ also was not strong at the small scale. The mean concentrations of acetate and soil DOC were indistinguishable (p > 0.05) between the six depth layers. The results of this study confirm methane production is probably one of the biogeochemistry processes bearing the most distinct spatial variability in soil.

Klemas, V., 2015. Remote sensing of floods and flood-prone areas: An overview.

River floods and coastal storm surges affect the lives of more people than most other weather-related disasters. Floods can destroy homes, roads, and bridges; tear out trees; cause mudslides; and take many human lives. During flooding, timely and detailed situation reports are required by disaster management authorities to locate and identify affected areas and to implement damage mitigation. Remote sensing systems on satellites and aircraft can provide much of the required information for delineating the flood-affected areas, assessing the damage, and feeding models that can predict the vulnerability to flooding of inland and coastal areas. In this article, I provide an overview of remote sensing and modeling techniques for forecasting the vulnerability to flooding of an area, determining the extent and intensity of the flooding, and assessing the damage caused by the flood.

Sealey, K.S. and Patus, J., 2015. Resources, methods, and effort associated with ESI mapping of the Bahamian archipelago for Great Exuma, Bahamas.

With the expanding exploration and transportation of petroleum products through Bahamian waters, a growing gap in coastal protection is an Environmental Sensitivity Index (ESI) mapping dataset of the entire archipelago. The resources required for coastal classification, ranking, and GIS mapping for one island, Great Exuma, are documented as a cost-effective methodology to protect all Bahamian shorelines. The ESI mapping follows international conventions for oil spill response planning, but because of the lack of a national coastal management structure, a relational database was developed to bring together field photographs, geology, and wildlife occurrence information to initiate the mapping process. The final product for Great Exuma was 13 ESI maps for one island environs, each map covering about 120 square km. The ESI mapping requires three types of expertise: (1) GIS (ESRI ArcMap 10.2) and relational database (Microsoft Access) expertise; (2) coastal ecology and geomorphology expertise; and (3) local resource management and natural history expertise. After initial field work of 14 days on the island, the GIS and coastal classification datasets required about 5 weeks for compilation. The datasets are dynamic and can be updated as new information becomes available. The ESI maps and coastal classification database are easily shared and revised moving forward. The process could be facilitated by the participation of citizen scientists to contribute photographs and local reports on status and changes to coastal resources. The overall ESI mapping product can provide a valuable management tool not only for oil spill response but for better integrated coastal zone management.

Aragonés, L.; López, I.; Villacampa, Y.; Serra, J.C., and Saval, J.M., 2015. New methodology for the classification of gravel beaches: Adjusted on Alicante (Spain).

In this article, a methodology is presented for the classification of gravel beaches, which can be applied internationally. Such beaches' defence against the energy of incoming water flow is due to their steep slopes and the high permeability of infiltration, but that defence is reduced with increasing sand fraction. The objective of this research was to understand the variables involved in the formation of gravel beaches, to classify them according to the distribution and position of sediment along the transversal profile, and to obtain a discriminant function. To apply the methodology, 34 gravel beaches in the province of Alicante, Spain, were first classified visually into five different types: Type 1: Sand and gravel beaches, Type 2: Sand and gravel separated beaches, Type 3: Gravel and sand beaches, Type 4: Gravel and sand separated beaches, and Type 5: Pure gravel beaches. In addition, a major study was performed to reduce the number of variables because one of the concerns was to find the variables that characterize and classify the beaches. Thus, the 45 variables, grouped according to material characteristics, wave, boundary conditions, and geometry of the beach, were first reduced to 25 by making comparisons among them and the type of beach and were finally reduced to 14 using the discriminant method. Note the use of the important variable Posidonia oceanica in the Mediterranean area, which, because of the changes produced in the swell, was actively involved in the classification. Finally, the discriminant function obtained was validated.

Miyazaki, Y.; Murase, A.; Shiina, M.; Masui, R., and Senou, H., 2015. Integrating and utilizing citizen biodiversity data on the Web for science: An example of a rare triggerfish hybrid image provided by a sport fisherman.

We report a photograph of the rare triggerfish hybrid, Rhinecanthus aculeatus × R. rectangulus (order Tetraodontiformes; family Balistidae), from Miyako-jima Island, Ryukyu Islands, southern Japan, that was provided by a sport fisherman via WEB sakana-zukan (an online photographic database of fish in Japan). The image was registered in the Fish Image Database of the Kanagawa Prefectural Museum of Natural History to make it available for scientific scrutiny. Here we emphasize the importance of communication between citizens, such as fishermen, scuba divers, and others, and experts via the Internet, to make possible the processing of biodiversity information provided by citizens into museum collections. This communication contributes Global Biodiversity Information Facility data for various biological studies, such as those on taxonomy, morphology, fauna/flora, community ecology, and biogeography.